After searching and reading (alot) I still haven't read any posts from anyone who can diffinitavley say the electric fan is woth it or not based on experience! Just alot of people speculating or quoting what they heard! Who has done it? I'm getting the plugs changed and thinking of adding the Flexalite dual electric fan kit in hopes to gain 3-4 mpg!
Yes I know it's a big truck and I knew it got poor gas mileage when I bought it but why should that stop me from modifying the truck in an effort to gain more?

I have the 5.4 w/ 85K miles
A4WD
K&N FIPK
Flowmaster Cat Back
BFG All terrains (stock size)
It has the roof rack and a rear spoiler (I guess to keep dirt off the rear window?)
I have Royal Purple in the front and rear diffs and the T-case.
I'm going to be switching to Royal Purple in the tranny as well and synthetic oil changes .

So with all that being said, what do you think I should be getting city/hway?

Just for fun I thinking 14/18! Am I crazy?

 

I get about that with my 5.4 Expy, and it is bone stock with the exception of haveing a drop in K&N filter.

 

I have also considered installing an electric fan for my 2003 4.6 Expy, but most of my research just turns up more questions. It is my understanding from older Ford trucks I have owned that the belt driven fans are usually engaged with a thermostatic type clutch which for the most part is not engaged during highway driving. Thus minimal if any loss of gas mileage or horsepower. So does an electric fan really only benefit you in horsepower/gas mileage for city or stop and go driving? Would it be more beneficial in the long run despite higher initial costs for other upgrades? For example I found an article on at diynetwork where they upgrade an '04 F150 with headers, new cold air intake, throttle body spacer, performance exhaust and reflashed the computer with a flash tuner. Has anyone had significant performance with any of these upgrades to justify their cost?


http://www.diynetwork.com/diy/ab_auto_fuel_system/article/0,2021,DIY_13679_5061136,00.html

 

Even with the OEM clutch "disengaged",there's still parasitic drag on the crankshaft which will lead to wasted fuel. I HAVE changed out my clutched fan for an electric,and it will IN FACT yeild a 2-3 MPG gain over the mechanical clutched version.
As for the cold air intakes and throttle body spacers-they will yeild you absolutely NOTHING in gains for fuel mileage. CAI's are a waste of money-the OEM tubing and airboxes are more than sufficient to supply the engine with air,and also pull air from outside the engine compatment,not from inside through an open element air filter. Throttle body spacers are the biggest joke out there aside from the tornaddo,and the theory behind it is even flawed for an EFI application. DOn't waste any money on those garbage items.
JL

 

Johhny thank you for your input! Even two miles to the gallon is a sweet increase, 2 mpg x 30 gal tank = 60 miles per tank which translates to a fillup savings of around 15-22 dollars depending on gas cost in your area! If you fill up once a week the fan would pay for itself in 4-6 months! thanks again!

 

Thanks alot Johnny. I now have a shadetree project for an upcoming weekend real soon.

 

I may be exsagerating a little but with an E fan/long tube headers and a good tune on the computer you could pick up 50 + HP.

 

I would imagine that is totaly do-able the problem is you want to hit the loud pedal harder when you have more power and sound! I know that's part of my problem just with the cat back!

 

I have the Flex-a-lite 270 kit on order for my 2004 3V. The only problem now is that the Flex-a-Lite web site does not have any instructions for installing their fans on any vehicle newer than 2003, sure you can search the web and this forum and find losts of info on installing it on a 2V, but the fuse box moved from the engine compartment to the cab and things are a little different on the 3V's. I just hope that I won't need detailed instructions to get the job done. Most of the hardware looks the same, I don't think that will be a problem. It's finding the circuits within the fuse box to connect up the Power On and AC On that might be a challange.

 

Yeah exaggerating a little, but on the right track. Here are my 2 or 3 cents on the Electric Fan - basis of this thread:

1. DO NOT put a Flex Lite Fan it. They are prone to failure, and their CFM's are pretty much exxagerated. Look into a Lincoln Mark VIII Fan, or one of the Mustang, or Taurus Fans. The Mark VIII fan wants to take off when you fire it up, and they can be picked up for around $60 (I just sold a leftover from my Mustang stuff a few months ago).

2. GO to Corrall.net and look up a controller for it. This slick unit adjusts the fan speed according to the temp, instead of a simple on/off. Does two things - reduces the loading, as well as reduces the hysteresis on the temp of the engine.

Mark VIII Fan

 

WOW DUDE! thanks for the heads up! I can seriously save some bucks here! I'm a little more than inclined with the working on my rig so this should make for a fun project! Thanks again.

 

Good information. I use a DC controller and a Tarurs fan on my Thunderbird.

However, I have some comments.

I have never heard that Flex-a-Lite fans were unreliable, at least not any more unreliable that any other electric fan and most of the time it's the controller not the fan that goes out.

The FAL 270 comes with a variable speed controller. Has two 15" fans capable of 3300 to 5500 CFM. Two fans mean that there will be better coverage across the radiator and provide better reliability than a single fan. The FAL controller provides control over the AC and gives options for manual control. The FAL 270 kit also comes with its own shroud that provides a finished look, rather than cutting up something to make it fit.

 

Aftermarket fans are a pile of crap.Their motors are tiny,and not capable of high load for long term-they will fail. The CFM ratings they claim are very overrated,and are not rated installed with any kind of restriction.
Ford's OEM fans are rated for 100K miles useage,have oversized motors with heavy gauge copper windings and are a durable,high power motor. I put a used Tbird fan(40K miles of useage) on my F150 (same dimensions as the Mark 8 fan),and it's been on ther for around 100K miles now-still as strong as the day I installed it.
JL

 

I put Flexalite fans on my 99, 5.4 in 2002 and have noticed a MPG increase of 1.5 to 2.
I have almost 100K, (129,400 Miles) on it since installation. The A/C connection was made in the + wire going to the A/C Compressor. I also put a switch in this connection so I could turn the fans off while driving > 40 MPH. The thermostat will still turn the fans on if the engine temp graches the setpoint. Works GOOD for me.

 

I have the fan kit from Troyer Performance. It has 2 heavy duty 16 inch fans. I have about 75 k on the kit with no problems. The only problem I've heard about on this kit was the controllers going out. I gained about 2 mpg with this kit.